The transit agency connecting Philadelphia and New Jersey said in a tweet on its account that delays of up to 20 minutes on both the east and west lines are due to "technical difficulties."

A spokesman for the Delaware River Port Authority was not immediately available.

At about 5:30, PATCO said on its website that riders should expect "significant delays" because of another train malfunction.

"At 5:16 p.m., a motor shorted-out on a six-car train headed eastbound onto the Benjamin Franklin Bridge. The first two cars are filling with smoke and passengers are being evacuated," PATCO said in a statement. "No reported injuries. Rush hour passengers are advised to expect significant delays."

One rider reported smoke inside the train cars, which had come to a complete stop.